JP6845113B2 - Radar device and radar signal processing method - Google Patents

Description

Embodiments of the present invention relate to radar devices and radar signal processing methods.

In a radar device using a conventional wideband phased array antenna, a grating lobe, which is an unnecessary radiated wave, may be generated. When the reflected wave from the target is received with the grating lobe generated, it is difficult to distinguish whether the received signal is the reflected wave by the main lobe or the reflected wave by the grating lobe. Therefore, it is necessary to determine whether the received signal is a reflected wave by the main lobe or a reflected wave by the grating lobe.

Japanese Unexamined Patent Publication No. 2005-164370

An object to be solved by the present invention is to provide a radar device capable of determining whether a received signal is a reflected wave by a main lobe or a reflected wave by a grating lobe, and a radar signal processing method.

The radar device of the embodiment includes an antenna device, a transmission control unit, a reception data generation unit, and a determination unit. The transmission control unit sequentially causes the antenna device to radiate radiated waves having frequencies different from each other in a predetermined directivity direction. The received data generation unit generates received data in which a value indicating the intensity of the reflected wave is associated with each frequency based on the reflected wave received by the antenna device. The determination unit adds the reception data generated by the reception data generation unit with respect to the frequency and compares it with the threshold value to selectively recognize the object existing in the predetermined direction direction and determine the target object.

The block diagram which shows the structural example of the radar apparatus 1 of embodiment. The block diagram which shows the structural example of the received data generation part 120 of embodiment. The figure for demonstrating the range-doppler data and cell of an embodiment. The first figure explaining the example of the characteristic of a reflected wave. The second figure explaining the example of the characteristic of the reflected wave. FIG. 3 illustrates an example of the characteristics of the reflected wave. FIG. 6 is a conceptual diagram in which predetermined cells of the embodiment are arranged with range-doppler data for each scanning angle. The conceptual diagram which added the signal amplitude value of FIG. 5 for each frequency. The flowchart which shows the operation of the radar apparatus 1 of embodiment.

Hereinafter, the radar device of the embodiment and the radar signal processing method will be described with reference to the drawings.

FIG. 1 is a block diagram showing a configuration example of the radar device 1. The radar device 1 includes, for example, an antenna device 10, a circulator 20, a transmitting unit 30, a receiving unit 40, a storage unit 60, an input unit 70, a display unit 80, and a control unit 100. The radar device 1 may be mounted on a moving body and used while moving, or may be used in a stationary state.

The radar device 1 of the embodiment sequentially emits radiated waves of different frequencies in a predetermined direction direction, and receives the reflected waves reflected by the radiated waves at the target (hereinafter, also referred to as scanning). For example, the radar device 1 scans a radiated wave having a frequency f1 in the range of −90 degrees to +90 degrees with respect to the search center. Next, the radar device 1 scans the radiated wave having the frequency f2 in the range of −90 degrees to +90 degrees with respect to the search center. Further, the radar device 1 scans the radiated wave having the frequency f3 in the range of −90 degrees to +90 degrees with respect to the search center. That is, the radar device 1 scans a predetermined range a plurality of times using radiated waves having a plurality of frequencies different from each other.

The antenna device 10 is an antenna of any form having a certain degree of directivity. The antenna device 10 is, for example, a phased array antenna. The circulator 20 is a circulation circuit for separating transmitted / received signals. That is, the circulator 20 supplies the RF signal generated by the transmitting unit 30 to the antenna device 10, and supplies the reflected echo received by the antenna device 10 to the receiving unit 40 as a receiving signal.

The transmission unit 30 transmits an RF signal from the antenna device 10 to the space via the circulator 20 at a predetermined transmission cycle, for example, under the control of the transmission control unit 110. A part of the transmitted wave transmitted by the antenna device 10 is reflected by the object and received by the antenna device 10 as a reflected echo. The transmission unit 30 includes, for example, a phase shifter (not shown), and the phase shifter changes the excitation phase of each antenna element in the phased array antenna. As a result, the transmitting unit 30 controls the radiated electric field of each antenna element so as to be in phase with each other in a predetermined direction to form a transmitting beam.

The receiving unit 40 generates a radar reception signal based on the signal supplied from the antenna device 10 at a cycle based on the transmission cycle in which the transmitting unit 30 generates the RF signal. The receiving unit 40 outputs the generated radar reception signal to the control unit 100.

The storage unit 60 is realized by, for example, a RAM (Random Access Memory), a ROM (Read Only Memory), an HDD (Hard Disk Drive), a flash memory, or the like. Various information referred to by the control unit 100 is stored in the storage unit 60. Further, when the control unit 100 includes a processor such as a CPU (Central Processing Unit), the storage unit 60 may store a program executed by the processor.

The input unit 70 receives an input operation by the operator of the radar device 1. The input operation received by the input unit 70 is converted into a signal indicating the content of the input operation and supplied to the control unit 100. The display unit 80 is realized by an LCD (Liquid Crystal Display), an organic EL (Electroluminescence) display device, or the like. The display unit 80 displays the result processed by the control unit 100.

The control unit 100 includes a transmission control unit 110, a reception data generation unit 120, and a determination unit 130. These functional units are realized by, for example, a processor such as a CPU executing a program (software). In addition, some or all of these functional parts may be realized by hardware such as LSI (Large Scale Integration), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), or software. And hardware may work together.

The transmission control unit 110 controls the transmission unit 30 to sequentially radiate radiation waves having frequencies different from each other toward the antenna device 10 in a predetermined directivity direction. The transmission control unit 110 generates, for example, an RF signal having a predetermined frequency, and outputs the generated RF signal to the transmission unit 30.

The reception data generation unit 120 generates reception data in which a value indicating the intensity of the reflected wave is associated with each frequency based on the reflected wave received by the antenna device 10. The reception data generation unit 120 acquires the reflected wave from the reception unit 40, generates the reception data, and outputs the generated reception data to the determination unit 130.

The determination unit 130 adds the received data generated by the reception data generation unit 120 with respect to the frequency and compares it with the threshold value to selectively recognize the object existing in the predetermined pointing direction and determine it as the target object. .. When the value of the added received data is equal to or greater than a predetermined threshold value, the determination unit 130 selects an object existing in the direction corresponding to the added received data as a target.

In addition, the determination unit 130 calculates the distance to the target object and the relative speed of the target object with respect to the selected target object. For example, the determination unit 130 calculates the distance to the target and the relative velocity of the target based on the intensity of the reflected wave that determines the direction of the target with respect to the own machine.

FIG. 2 is a block diagram showing a configuration example of the received data generation unit 120 of the embodiment. The reception data generation unit 120 includes, for example, a range-doppler data acquisition unit 122 and a correction unit 124.

The range-doppler data acquisition unit 122 converts the time-series received signal output from the reception unit 40 into a signal in the frequency domain, and acquires range-doppler data based on the converted frequency domain signal. Here, the range in the range-Doppler data is the distance from the radar device 1 to the target. The Doppler in the range-Doppler data is a Doppler frequency calculated based on the phase of the reflected wave received by the antenna device 10.

The correction unit 124 corrects the Doppler frequency in the range-Doppler data acquired by the range-Doppler data acquisition unit 122 based on the wavelength of the radiated wave. The correction unit 124 corrects the Doppler frequency based on the relational expression between the Doppler frequency and the speed shown in the following equation (1). Here, fd indicates the Doppler frequency, v indicates the velocity, and λ indicates the wavelength of the radiated wave. The velocity v in the equation (1) is the relative velocity of the target object with respect to the radiation direction of the radiated wave. Further, the velocity v is positive when the target object is approaching the radar device 1.

fd = 2 × v / λ ・ ・ ・ Equation (1)

The correction unit 124 corrects the Doppler frequency fd in each of the range-Doppler data acquired based on the radiation waves having different frequencies (wavelengths) so that the velocity v becomes the same value. For example, when the Doppler frequency fd1 in the range-Doppler data acquired based on the radiated wave of the wavelength λ1 is used as a reference, the correction unit 124 uses, for example, from Equation (1) that the Doppler frequency fd is inversely proportional to the wavelength λ of the radiated wave. The Doppler frequency fd2 in the range-Doppler data acquired from the radiated wave of wavelength λ2 is corrected to fd2 × λ1 / λ2 based on the relationship.

Here, the range-doppler data and the cell will be described with reference to FIG. FIG. 3 is a diagram for explaining the range-Doppler data and cells of the embodiment.

First, range-doppler data will be described. Range-Doppler data is data represented by a coordinate system consisting of a range axis, a Doppler axis, and a signal amplitude axis. Here, the range axis indicates the distance (range) from the radar device 1 to the target object. The range is calculated based on, for example, the time from emitting a radiated wave to receiving a reflected wave, and the speed of the radiated wave (speed of light). The Doppler axis indicates the Doppler frequency in the reflected wave. The Doppler frequency is calculated by, for example, frequency transforming (for example, DFT (Discrete Fourier Transform)) a reflected wave in a time series.

Next, the cell will be described. A cell is a region surrounded by a predetermined range in the range axis direction and a predetermined range in the Doppler data axis direction. The width in the range axis direction and the width in the Doppler axis direction corresponding to one cell may be arbitrarily determined.

In the example of FIG. 3, it is shown that the signal amplitude becomes the maximum (peak) at the Doppler axis coordinate B with respect to the characteristic H of the Doppler frequency at the range axis coordinate A. This indicates that, for example, there may be a target moving at a relative speed corresponding to the Doppler axis coordinate B at a distance corresponding to the range axis coordinate A. However, in the configuration of the embodiment, it is difficult to determine whether the characteristic H is a characteristic based on the reflected wave for the main lobe or a characteristic based on the reflected wave for the grating lobe.

Here, the reflected waves of the main lobe and the grating lobe will be described. The reflected wave by the main lobe is reflected by an object in the same direction (front) as the radiation direction of the radiated wave. On the other hand, the reflected wave by the grating lobe is a reflected wave of the grating lobe radiated in a direction different from the radiation direction of the radiated wave and reflected on the object. In other words, when the main lobe is radiated, the grating lobe is also radiated, so an object that is not in front is erroneously detected as if it were an object in front. In order to avoid such false detection, it is necessary to selectively extract the reflected wave for the main lobe from the state in which the reflected wave from each of the main lobe and the grating lobe is mixed. Hereinafter, a method for selectively extracting the reflected wave for the main lobe will be described.

First, the characteristics of the reflected wave will be described with reference to FIGS. 4 to 6. FIG. 4 is a first diagram for explaining the characteristics of the reflected wave. Graph G1 of FIG. 4 is a diagram illustrating a state in which a radiated wave is radiated in the direction of the scanning angle θ1 when the object T exists in the Y-axis direction in the XY coordinate space. Further, each of the graphs G2 to G4 is range-doppler data acquired based on each reflected wave when the radiated wave has frequencies f1 to f3, respectively. The gray portion shown in each of the graphs G2 to G4 indicates the area of the same cell.

When there is an object T in the Y-axis direction and the radiated wave is radiated in a direction with a scanning angle θ1 different from the Y-axis direction, the radiated wave travels straight without being reflected by the object and is a range acquired based on the reflected wave. -It is considered that the peak of the signal amplitude value does not appear in the Doppler data.

However, as shown in graph G2, a peak of the signal amplitude value appears in a certain cell even though no object exists in the direction of the scanning angle θ1 with respect to the radiated wave having the frequency f1. This is because the grating lobe is radiated in a direction different from the direction of the main lobe (the direction of the scanning angle θ1), and the direction in which the grating lobe is radiated happens to overlap with the direction in which the object T is (Y-axis direction), and the grating lobe is It is probable that the reflected wave reflected on the object T was received. In this case, since there is a possibility that the peak of the cell may erroneously recognize that there is an object in the direction of the scanning angle θ1, it is necessary to exclude the reflected wave for the grating lobe from the reflected wave.

On the other hand, as shown in the graph G3, the peak of the signal amplitude value does not appear in the cell with respect to the radiated wave having the frequency f2. This is because the main lobe and the grating lobe of the radiated wave are not directed in a certain direction (Y-axis direction) of the object T, and the radiated wave is not reflected on the object T.

Similarly, as shown in the graph G4, the peak of the signal amplitude value does not appear in the cell with respect to the radiated wave having the frequency f3. This is because the main lobe and the grating lobe of the radiated wave are not directed in a certain direction (Y-axis direction) of the object T, and the radiated wave is not reflected on the object T.

FIG. 5 is a second diagram for explaining the characteristics of the reflected wave. Graph G5 of FIG. 5 is a diagram illustrating a state in which a radiated wave is radiated in the direction of the scanning angle θ2 when the object T exists in the Y-axis direction in the XY coordinate space. Further, each of the graphs G6 to G8 is range-doppler data when the radiated waves have frequencies f1 to f3, respectively. The gray portion shown in each of the graphs G6 to G8 indicates the area of the same cell.

As shown in graph G6, since the main lobe and grating lobe of the radiation wave are not directed in a certain direction (Y-axis direction) of the object T with respect to the radiation wave of frequency f1, the signal amplitude value of the signal amplitude value in a certain cell. No peak appears.

As shown in the graph G7, since the grating lobe is directed in a certain direction (Y-axis direction) with respect to the radiated wave having the frequency f2, the peak of the signal amplitude value appears in the cell.

As shown in the graph G8, since the main lobe and the grating lobe of the radiation wave are not directed in the direction (Y-axis direction) of the object T with respect to the radiation wave of the frequency f3, the signal amplitude value in the cell concerned. No peak appears.

FIG. 6 is a third diagram for explaining the characteristics of the reflected wave. Graph G9 of FIG. 6 is a diagram illustrating a state in which a radiated wave is radiated in the direction of the scanning angle θ3 (= Y-axis direction) when the object T exists in the Y-axis direction in the XY coordinate space. .. Further, each of the graphs G10 to G12 is range-doppler data when the radiated waves have frequencies f1 to f3, respectively. The gray portion shown in each of the graphs G10 to G12 indicates the area of the same cell.

As shown in the graph G10, since the main lobe is directed in a certain direction (Y-axis direction) with respect to the radiated wave having the frequency f1, the peak of the signal amplitude value appears in a certain cell.

As shown in the graph G11, since the main lobe is directed in a certain direction (Y-axis direction) with respect to the radiated wave having the frequency f2, the peak of the signal amplitude value appears in the cell.

As shown in the graph G12, since the main lobe is directed in a certain direction (Y-axis direction) with respect to the radiated wave having the frequency f3, the peak of the signal amplitude value appears in the cell.

From the results of FIGS. 4 to 6, when focusing on a certain scanning angle, when the signal amplitude values in a predetermined cell when the radiated wave is radiated while changing the frequency are summed, there are cases where there is an object in the direction of the grating lobe. There is a significant difference in the total value when there is an object in the direction of the main lobe. Utilizing this, in the radar device 1 of the present embodiment, it is determined whether or not the object is detected by the main lobe by comparing the total value obtained by adding the signal amplitude values for each predetermined cell with a predetermined threshold value. , Objects detected by the main lobe are selectively extracted by excluding the objects detected by the grating lobe from the detection results.

Next, a method of extracting the reflected wave for the main lobe will be described with reference to FIGS. 7 and 8. FIG. 7 is a diagram showing a conceptual diagram in which range-Doppler data of a predetermined cell of the embodiment are arranged in the scanning angle direction of the transmission beam. The upper part of FIG. 7 is the data when scanned with the radiated wave of frequency f1, the middle part of FIG. 7 is the data when scanned with the radiated wave of frequency f2, and the lower part of FIG. 7 is the data when scanned with the radiated wave of frequency f3. Are shown respectively. Further, the horizontal axis in each of the upper, middle, and lower stages of FIG. 7 indicates the direction of the scanning angle of the transmission beam (described as Sin θ (scanning angle) in FIG. 7), and the vertical axis indicates the signal amplitude.

As shown in the upper part of FIG. 7, when a predetermined scanning angle range is sequentially scanned by a radiated wave having a frequency f1, peaks P1 to P7 of signal amplitude values are shown at each of scanning angles D1 to D7. Some of these peaks are detected from the main lobe, and the rest are peaks detected from the grating lobe.

As described with reference to FIGS. 4 to 6, the scanning angle of the peak detected from the main lobe coincides with the direction in which the object exists, but the scanning angle of the peak detected from the grating lobe does not necessarily correspond to the direction in which the object exists. It does not match. That is, among the peaks P1 to P7 shown in the upper part of FIG. 7, those showing the peak detected from the grating lobe has no object in the direction corresponding to the peak.

As shown in FIG. 7, for the scanning angle D1 corresponding to the peak P1 at the frequency f1, there is no peak at the frequency f2 and no peak at the frequency f3. Similarly, for the scanning angle D2 corresponding to the peak P2 at the frequency f1, there is no peak at the frequency f2 and no peak at the frequency f3. Further, for each of the scanning angles D5 to D7 corresponding to each of the peaks P5 to P7 at the frequency f1, there is no peak at the frequency f2 and no peak at the frequency f3. Therefore, it is considered that the peaks detected for each of the scanning angles D5 to D7 are detected from the grating lobe.

On the other hand, for the scanning angle D3 corresponding to the peak P3 at the frequency f1, there are a peak P10 at the frequency f2 and a peak P17 at the frequency f3, respectively. Similarly, for the scanning angle D4 corresponding to the peak P4 at the frequency f1, there are a peak P11 at the frequency f2 and a peak P18 at the frequency f3, respectively. Therefore, it is considered that the peaks detected for each of the scanning angles D5 and D6 are detected from the main lobe.

FIG. 8 shows a conceptual diagram in which the signal amplitude values of FIG. 7 are added up for each frequency for a predetermined scanning angle. Further, the horizontal axis in FIG. 8 indicates the direction of the scanning angle of the transmission beam (described as Sinθ (scanning angle) in FIG. 8), and the vertical axis indicates the signal amplitude. Further, Th on the vertical axis of FIG. 8 indicates a predetermined threshold value.

In the example of FIG. 8, the signal amplitude values of the scanning angles D3 (D10, D17) and D4 (D11, D18) each show a prominent peak value, but the other scanning angles (D1, D2, D5 to D7, For D8, D9, D12 to D14, D15, D16, D19 to D21), the signal amplitude value is smaller than any of the scanning angles D3 (D10, D17) and D4 (D11, D18).

The determination unit 130 sums the range-Doppler data of the frequencies f1 to f3 for the predetermined scanning angles (θ1, θ2 ...), And the peak of the summed signal amplitude value is equal to or higher than the predetermined threshold Th. If so, it is determined to have been detected in the main lobe. Here, the predetermined threshold Th is, for example, the smaller of the signal amplitude values of the scanning angles D3 and D4 and the signal amplitude values of the other scanning angles (D1, D2, D5 to D7). It is set between the one with the largest value. In this way, the determination unit 130 selects the reflected wave for the main lobe from the signal in which the reflected waves from the main lobe and the grating lobe are mixed by comparing the peak of the total signal amplitude value with the predetermined threshold value Th. Extract to.

Here, the operation of the radar device 1 will be described with reference to FIG. FIG. 9 is a flowchart showing the operation of the radar device 1 of the embodiment. As a premise of this flowchart, the maximum value of the number of scans to be repeatedly executed (maximum number of scans Nmax) is predetermined, and the frequency of the radiated wave corresponding to each number of scans N (1 ≦ N ≦ Nmax) is predetermined. It is assumed that

First, the radar device 1 initializes a variable indicating the number of scans N (step S1). The variable indicating the number of scans N is, for example, a variable stored in the storage unit 60. Next, the radar device 1 determines whether or not the number of scans N is equal to or greater than the predetermined maximum number of scans Nmax (step S2).

In step S2, when the number of scans N is less than the predetermined maximum number of scans Nmax, the radar device 1 executes the scan. The radar device 1 radiates a radiated wave from the antenna device 10 at a predetermined frequency f determined in advance corresponding to the number of scans N, and executes a scan (step S3). Next, the range-doppler data acquisition unit 122 of the radar device 1 acquires range-doppler data based on the reflected wave received by scanning (step S4). Next, the correction unit 124 of the radar device 1 corrects the Doppler frequency of the range-Doppler data (step S5). Next, the radar device 1 arranges the range-Doppler data in the scanning angle direction for each cell of the corrected range-Doppler data (step S6). Then, the radar device 1 increments the variable indicating the number of scans N and performs the process shown in step S2.

On the other hand, in step S2, when the number of scans N is equal to or greater than the predetermined maximum number of scans Nmax, the determination unit 130 of the radar device 1 adds the range-doppler data acquired for each scan (step S8). Next, the determination unit 130 determines the presence or absence of a target by comparing the signal amplitude value with a predetermined threshold value from the added data (step S9). Then, the determination unit 130 calculates the distance from the value of the range corresponding to the cell determined to have the target to the target, and calculates the relative speed of the target from the value of the Doppler corresponding to the cell (step S10).

As described above, the radar device 1 of the embodiment includes an antenna device 10, a transmission control unit 110 that sequentially emits radiation waves of different frequencies to the antenna device 10 in a predetermined direction direction, and an antenna device. Received data generation unit 120 that generates received data associated with a value indicating the intensity of the reflected wave for each frequency based on the reflected wave received by 10, and received data generated by the received data generation unit 120. Is provided with respect to the frequency, and the determination unit 130 is provided to selectively recognize the object existing in the predetermined pointing direction and determine the target object by comparing the data with the threshold value.

Thereby, the radar device 1 of the embodiment can determine whether the received signal is the reflected wave by the main lobe or the reflected wave by the grating lobe. This is because the determination unit 130 adds the received data generated by the reception data generation unit 120 with respect to the frequency, so that the reflected wave by the main lobe can be emphasized more than the reflected wave by the grating lobe.

Further, in the radar device 1 of the embodiment, the reception data generation unit 120 acquires range-doppler data based on a signal obtained by converting each of the reflected waves from a time-series signal to a signal in the frequency region. It has a unit 122 and a correction unit 124 that corrects the Doppler frequency in each of the range-Doppler data based on the frequency of the radiation wave, and the determination unit 130 has the Doppler frequency and the Doppler frequency in a predetermined cell determined to have a target. Based on the range, calculate at least one of the distance to the target and the relative speed of the target.

As a result, the radar device 1 of the embodiment can calculate not only the presence / absence of the target object but also the distance to the target object and the relative speed of the target object in addition to the above-mentioned effects. This is because the range axis in the range-Doppler data contains information corresponding to the distance to the target, and the Doppler axis contains information corresponding to the relative velocity of the target.

According to at least one embodiment described above, the radar device 1 of the embodiment is a transmission control that sequentially emits radiation waves of different frequencies to the antenna device 10 and the antenna device 10 in a predetermined direction direction. A reception data generation unit 120 and a reception data generation unit 120 that generate reception data in which a value indicating the intensity of the reflected wave is associated with each frequency based on the reflected wave received by the unit 110 and the antenna device 10. By adding the received data generated by the above with respect to the frequency and comparing it with the threshold value, the determination unit 130 for selectively recognizing the object existing in the predetermined pointing direction and determining the target object is provided. It is possible to determine whether the received signal is a reflected wave by the main lobe or a reflected wave by the grating lobe. This is because the determination unit 130 adds the received data generated by the reception data generation unit 120 with respect to the frequency, so that the reflected wave by the main lobe can be emphasized more than the reflected wave by the grating lobe.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, as well as in the scope of the invention described in the claims and the equivalent scope thereof.

1 ... Radar device, 10 ... Antenna device, 30 ... Transmission unit, 40 ... Reception unit, 100 ... Control unit, 110 ... Transmission control unit, 120 ... Reception data generation unit, 130 ... Judgment unit, 122 ... Range-Doppler data acquisition Unit, 124 ... Correction unit.

Claims (3)

Antenna device and
By changing the excitation phase of each antenna element in the antenna device, the radiated electric fields of each antenna element are controlled to be in common phase in a predetermined direction, and a plurality of different antenna elements within a predetermined scanning angle range with respect to the search center. the reflected waves radiated wave of the first frequency of the radiation waves of the first frequency causes release Isa in the direction of the scan angle is reflected by an object is received by the antenna device, the direction of the plurality of scan angle a transmission control section for the reflected wave reflected Ru is received by the antenna device by the radiation wave object a radiant wave is radiated the second frequency of the second frequency different from said first frequency Te,
A reception data generation unit that generates reception data in which a value indicating the intensity of the reflected wave is associated with the scanning angle of the radiated wave for each frequency based on the reflected wave received by the antenna device.
A value indicating the intensity of the reflected wave in the received data generated by the received data generation unit is associated with the specific scanning angle by comparing the value obtained by adding each frequency with the threshold value for the specific scanning angle. was reflected waves to determine reflected wave by the reflected wave or grating lobes by the main lobe, and a goal was the determination unit objects present in the direction of the scan angle of the reflected waves by the main lobe is received Radar device. The received data generation unit
A range-doppler data acquisition unit that acquires range-doppler data based on a signal obtained by converting each of the reflected waves from a time-series signal to a signal in the frequency domain.
It has a correction unit that corrects the Doppler frequency in each of the range-Doppler data based on the frequency of the radiated wave.
The radar device according to claim 1, wherein the determination unit calculates at least one of a distance to the target object and a relative speed of the target object with respect to the selected target object. By changing the excitation phase of the antenna device and each antenna element in the antenna device, the radiated electric field of each antenna element is controlled to be in common phase in a predetermined direction, and within a range of a predetermined scanning angle with respect to the search center. to receive some reflected waves radiated wave of one another by Isa release the radiation waves of the first frequency in the direction of the plurality of different scan angles the first frequency is reflected by the object to the antenna device, the plurality of scan angle and a transmission control section for the reflected wave reflected Ru is received by the antenna device by the radiation wave object a radiant wave is radiated the second frequency of the second frequency different from said toward the direction the first frequency The computer that controls the radar device
Based on the reflected wave received by the antenna device, received data in which the scanning angle of the radiated wave is associated with a value indicating the intensity of the reflected wave is generated for each frequency.
The generated value indicating the intensity of the reflected wave in the received data, for a particular scan angle, by comparing a value obtained by adding for each frequency to a threshold, the reflected wave corresponding to the specific scanning angle main It determines whether the reflected wave by the reflected wave or grating lobes due lobe, radar signal processing method for determining a goal was object present in the direction of the scan angle of the reflected wave is received by the main lobe.

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